An axially rotated valve and method

ABSTRACT

The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.

[0001] This patent is a continuation-in-part of U.S. application Ser.No. 08/637,203 by Robert K. Burgess, commonly owned by the Assignee, andfiled Apr. 24, 1996, now U.S. Pat. No. ______, entitled “AXIAL-MOUNTEDHIGH FLOW VALVE”.

I. FIELD OF INVENTION

[0002] The present invention relates to an improved flow rate valvesystem and valve, especially for axially-rotated valves and includesboth apparatus and methods. In particular, the present invention hasapplicability where a freeze resistant valve is preferred.

II. BACKGROUND OF THE INVENTION

[0003] Valves have been used for many centuries in a variety ofapplications. As the technology has progressed, more sophisticated useshave been found for valves. For instance, various improvements have beenmade in methods of actuation of the valve. Some of these methods includemotor driven actuation, solenoid actuation and more recently, computercontrolled actuation, and so forth. However, the essential flow designof valves has stayed relatively constant along four basic designs.

[0004] One type of valve used is a gate valve. It is simple in design,inexpensive, and can be used in a variety of applications. A gate valvetypically contains a circular disk, known as a gate, mounted transverseto a conduit or pipe which engages a seat to block or restrict flow. Agate valve is generally known to those in the art as being poor forcontrolling flow other than in a fully-opened or fully-closed position.The interface between the gate and its seat generally erodes and isprone to maintenance.

[0005] Another typical valve is known as a globe valve. Those in the artknow that it is good for throttling at other than fully-opened orfully-closed positions. An example is shown in U.S. Pat. No. 4,066,090to Nakajima et al. As can be seen, the flow path is somewhat circuitousresulting in generally higher friction losses, nonlaminar flow, and mayprematurely induce flow separation and/or cavitation. Thus, flow ratestend to be less than those of a fully-opened gate valve, the fluid flowpath tends to wear, and the globe valve, because of its inherentconstruction, tends to be bulky.

[0006] A third type is a ball valve. The ball valve may offer someadvantages of increased flow over the globe valve. The valve actuatorconnected to the ball is mounted transverse to the flow. As the valveopens, the ball is rotated and aligns a central hole in the ball to theconduit through the valve. The ball valve tends to be somewhat bulky,generally uses two seating surfaces on either side of the ball, and maybe somewhat expensive to manufacture.

[0007] A fourth type of valve is known as a butterfly valve. Thebutterfly valve has an internal seat that is typically orientedtransverse to the conduit. An external valve stem rotates typically acircular disk transverse to the conduit to engage the seat to blockfluid flow. A butterfly valve generally has high flow rates and lowmaintenance. However, it retains the typical construction of atransverse-mounted valve with a transverse valve stem. While the valvestem may be remotely actuated by motors and other devices known to thosein the art, it may not be suitable for sealed installations where itmight be desirable to completely encase the valve, remote actuator, andseat in a conduit for efficient installation nor is it suitable forinstalling in a wall structure where access to the actuator isrestricted because of the transverse orientation.

[0008] An underlying quest in the various designs of valves is a balancebetween low friction losses, high flow rates, and throttlingcharacteristics. Other considerations may include freeze resistance,simplicity of construction, cost of manufacturing, and perhaps otherspecialized uses. While there have been numerous variations of the valvetypes such as described above, there remains a need to provide animproved flow, low friction valve. This may be especially useful inapplications where a remote actuation along a central axis is desired.Typically, these installations involve freeze resistant installations.

[0009] In addressing freeze prevention or reduction, efforts have beenconcentrated on a remote location of a plug of a globe valve away fromambient conditions that could lead to freezing. A typical example isseen in FIG. 7 of U.S. Pat. No. 4,532,954. By remotely locating theplug, the flow of the liquid, typically water, could be stopped adistance in a pipe or a conduit away from the freezing ambientconditions. Those in the art typically concentrated on a globe valvetype seat because of the inherent difficulty of actuating a gate valvefrom within the conduit. In this construction, the nose portion engagesa valve seat to seal any flow at a remote location from adverse ambientconditions. As is shown in that figure, the nose must engage a valveseat through the aperture that restricts the flow of water. This remotelocation results in a beneficial blocking of the water away from thefreezing ambient conditions. However, it causes other problems. The wearsurfaces may be prone to water erosion and deposits from waterimpurities. Also, in order to obtain a proper seal, the mechanicaladvantage of the screw of the valve stem may, after much use, crush thetip of the nose portion. Once the nose was crushed or deformed, itrequired even harder tightening of the nose which eventually lead toleaking (the famous “drip drip”). Also, the inherent design of the noseportion, engaging an aperture, causes a significant pressure drop, asthose with ordinary skill in the art would immediately recognize. Thissignificant pressure drop reduces flow rates. Reduced flow rates maycause a necessarily proportional increase in the size of conduit, valve,or other devices to obtain the needed flow rates. Additionally, the useof the nose section was a modification of the globe valve type seatwhich required many turns to suitably seal the flow. Likewise, the valvecontrol rod (stem) moved in the typical longitudinal direction—it wasnot fixed with respect to the conduit or pipe in which it was assembled.Therefore, increased wear and increased maintenance resulted from notonly the rotational movement, but the longitudinal movement as itengaged those portions of the valve seat. While an increase in size ofthe typical valve might achieve the necessary flow rates, typically,this was not a viable option because of size, costs, and compatibilitywith other components of the piping system.

[0010] Thus, prior attempts to remotely seal the water flow or otherliquids lead to high pressure drops, low flow rates, and maintenance.The flow rate is especially important in designing sprinkling systems.Both residential and commercial sprinkler systems require a higher flowrate than the typical gate valve or globe valve delivers for giventypical size. Thus, an installation was not able to use the typicalvalving of a typical freeze resistant hydrant—instead, it required adirect connection to other piping with sophisticated valving controls.The sophisticated valving, as those with knowledge of sprinkler systemswould recognize, required expensive controls, maintenance, purgingduring off-season uses, local and national codes, and other issues.

[0011] A further complication resulted from the axially rotated valvessuch as the valves referenced above and others such as U.S. Pat. No.3,848,806 to Samuelsen, et al. This actuation shows that the valve stemon such axially-rotated valves has been heretofore in the flow path.Until the present invention, on such axially-rotated valves, it may havebeen considered by those in the art that the valve stem was required tobe placed in the flow path in order to engage remotely the nose portionto the aperture. However, the additional turbulence and volume containedby the valve stem in the flow path results in additional loss ofefficiency, increased resistance and friction, and lower flow rates.

[0012] Thus, as systems have become more sophisticated, a need existsfor a valve that can be remotely actuated through the internal structureof a valve away from adverse ambient conditions, and yet be inexpensive,easily installed, of the same or similar diameter to existing pipingsystems, and still maintain high flow rates and low pressure drops. If asystem was available that would allow a high flow rate water hydrantthat could be converted to a combination system and water hydrant, itwould have an advantage in the market. It would be advantageous to thedwelling owner in a reduction of cost, and it would be advantageous tothe builder or installer to simply meet the building requirements ofinstalling outside faucets and yet allow conversion to sprinkler systemsat minimal costs.

[0013] A significant improvement over the typical valves was attained inthe U.S. application Ser. No. 08/637,203, now issued as U.S. Pat. No.______ to Robert K Burgess and upon which this patent claims a prioritydate. In that patent, it was realized that a fixed longitudinal positionwith axial rotation could establish high flows and less pressure dropand friction loss and perhaps less maintenance and less costlyinstallations because of its compactness. In that patent, the inventionprovided a specially designed valve that had a rotatable sealing elementlongitudinally fixed in position in a conduit which engaged a seatingelement likewise longitudinally fixed in position in the conduit. Theposition could be located a sufficient length or distance from forinstance, adverse ambient conditions to enable a sealing of flow awayfrom the adverse conditions. That valve significantly improved the flowrates compared to the state of the art known at that time. Test resultssuggest that the globe valve might have up to approximately 2 times thepressure loss for a given flow rate than the Burgess invention.Similarly, the Burgess invention appears to have about five times lessfriction loss than the design shown in the '954 reference above. Thisinvention also allowed a quarter turn from a fully-opened to afully-closed position. Because of its increased flow, it was felt thatit would provide a valve of suitable flow rates that could be installedin the same size as a typical conduit and yet meet even the moredemanding sprinkler systems requirements. Among other things, however,that valve retained the typical valve stem located in the flow path.

[0014] As an example of the significant improvement in pressure drop bythe present invention, FIG. 1a shows the pressure drop as a function offlow rate for various commercially available axially-rotated freezeresistant valves. FIG. 1b shows a graph of measured loss coefficients asa function of Reynolds number for the present invention compared to somecommercially available axially-rotated valves and other types of valves,again to show some of the significant improvements of the presentinvention. The two top curves show valves by competitors, such as aredesigned for higher flow rates on sprinkler feed systems. Although the'203 valve appeared to have significant improvement over technologyexisting at the time, the present invention shows an even greater flowrate for a given pressure drop or conversely a lower pressure drop at agiven flow rate. The present invention may have a 4 times improvementover some of the competition when based on pressure drops at a givenflow rate.

[0015] Another reference, U.S. Pat. No. 286,508 to Vadersen, et al.,shows an early attempt in providing an axially-rotated freeze resistantvalve. For some reason, the embodiment apparently was not receivedcommercially. Perhaps, two reasons exist. First, the valve plate (G)with apertures (H), when aligned with valve (K) in apertures (T), asthose with ordinary skill in the art would readily recognize, wouldcreate nonlaminar flow, increased friction loss, flow separation, andperhaps cavitation (depending on the vapor pressure of the fluid at thattemperature). Secondly, the valve stem appears located in the flow path.This is in direct contrast to the present invention which in someembodiments uses an axially-rotated split venturi to avoid the problemsof the Vadersen reference. Thus, it may be that from the Vadersenreference to the present invention of 114 years, little improvementsalong this particular line appear to have been thought appropriate.

[0016] The present invention goes beyond the inventions of the earliervalves and even the U.S. application Ser. No. 08/637,203. The presentinvention improves the flow rates for a given supply pressure severaltimes over the '203 invention. It has a loss coefficient lower than anyknown axially rotated valve. Its loss coefficient has been tested andmay be approximately 50% of a typical axially rotated valve. It may beeven simpler to construct, typically avoids the valve stem in the flowpath, offers good throttling characteristics, and yet retains higherflow rates for given pressure drops.

[0017] Thus, there has been a long felt, but unsatisfied need for theinvention that would meet and solve the problems discussed above. Thepresent invention represents the next step in the quest for lowfriction, high flow and good throttling characteristics, especially inapplications where remote actuation of axially-rotated valves isdesired. While implementing elements have all been available, thedirection of the inventions of other persons have been away from thepresent invention. The efforts have primarily concentrated onlongitudinally moving backward or forward a nose or other sealingelement against a valve seat, typically including an aperture. This hasresulted in the above-discussed problems, such as poor flow rates. Thosein the art appreciated that a problem existed and attempted to solve theproblem with technology as shown in Pat. No. 4,532,954. Even with theimprovements of the invention of U.S. Ser. No. '203, the problem stillexisted at less than optimal flow rates for given pressure drops.Alternatively, those in the art simply accepted the extra expense ofextra installations, complicated valving, and other requirementsnecessary for such applications as sprinkler systems. This general mindset taught away from the technical direction that the present inventionaddresses. It might be unexpected that a valve can have significantlyhigher flow rates and yet remotely control or block the fluid flow withthe same or similar size conduit or pipe found in a typical installationand still offer an economical solution. Until the present invention, itappears that those skilled in the art had not contemplated the solutionoffered by the present invention.

III. SUMMARY OF THE INVENTION

[0018] A primary goal of the present invention is to provide a designwhich permits increased flow rates for axially-rotated valves,especially those used in freeze resistant prevention valves andsprinkler systems. By recognizing and utilizing the advantages of awholly different layout and design of a valve, this valve achieves itsgoals.

[0019] The present invention provides an axially-rotated valve whichpermits increased flow rates and lower pressure drop by using an axialeccentric split venturi with two portions where at least one portion isrotatable with respect to the other portion. (As would be known to thosewith ordinary skill in the art, a typical venturi is a conicalcontraction then expansion of a conduit through which a fluid flow.Venturies typically are high efficiency devices primarily used formeasuring the flow rates of fluids, see e.g., Beckwith, Thomas,Marangoni, Roy, Lienhard V, John, Mechanical Measurements p. 617(Addison-Wesley Publ. Co. 5th ed. 1993)). The axially-rotated valvetypically may be designed to avoid flow separation and/or cavitation atfull flow under a variety of conditions. The valve may be designed, insome embodiments, to delay a transition from laminar flow in at leastsome portion of the split venturi. A typical cross section of theeccentric split venturi may be non-axisymmetric such as a semicircularcross section which may assist in both throttling capabilities and inmaximum flow capacity using the design of the present invention. Such adesign can include applications for freeze resistant axially-rotatedvalves and may be fully-opened and fully-closed in one-half of acomplete rotation. An internal elbow typically connected to a rotatableportion of the eccentric venturi may assist in directing flow with lowerfriction losses and pressure drop. A valve actuator may actuate in anaxial manner yet be uniquely located outside of the axial flow path tofurther reduce friction losses. A seal may be used between the twoportions that may include a peripheral and diametrical seal in the sameplane.

[0020] Typically, the present invention may be envisioned as useful onresidential and commercial installations where it would be desirable toeconomically reduce the possibility of freezing of the valve. Suchapplications could also involve sprinkler systems, both underground andabove ground. Rather than supplying a system which affords only anincremental increase in performance and design over prior art, thepresent invention utilizes a technique to achieve significantperformance improvement compared to past efforts. The valve of thepresent invention satisfies one of the criteria by being inexpensive tomanufacture and yet offers high flow rates, good maintenance, lowpressure drop, and throttling capabilities.

[0021] This invention has a significant advantage in the sizing ofvalves and pipes. It retains the desirability of quickly opening andclosing from a fully-opened to a fully-closed position. At a fill flow,in some embodiments, the present invention seeks to sustain astreamlined, noncavitating flow, and in some embodiments, a somewhatlaminar flow. This may result in less turbulence and reduced frictionloss. This invention is particularly important in resolving thedifficulties with axially-rotated valves mounted in the flow stream andactuated along a longitudinal axis parallel to a central axis of thevalve in a flow direction.

[0022] Another goal of the present invention is to provide a design foran axially-rotated valve which permits increased flow rates and lesspressure drop using an axial eccentric split venturi with two portionswhere at least one portion is rotatable with respect to the otherportion. An objective of this goal is to provide an axial rotator torotate at least one of the portions without a substantial engagement ofthe axial rotator within the flow path. Another goal is to provide aneccentric split venturi approximating the shape of a semicircular crosssection in a direction transverse to the flow path which may assist inboth throttling capabilities and in maximum flow capacity with thedesign of the present invention. Such a design can include the object ofproviding a freeze resistant axially-rotated valve. It may be providedwith a length of at least six inside diameters (preferably seven oreight) of the portion, particularly the downstream portion, to assist inproviding smooth transitional flow through the split venturi. Anotherobjective may be to provide a cartridge assembly comprising at leastpart of the valve so that it may be easily retracted and inserted into aconduit of the valve. Such a design may be fully-opened and fully-closedin one-half complete rotation. While this may not be as rapidly openingas the embodiment shown in the '203 invention, it is believed that sucha rapid rotation will satisfy the goals and objectives of themarketplace. Also, the invention may include a purge port adapted toopen and allow drainage of the valve when the valve is in at least apartially closed position and typically in a fully-closed position. Byusing a split venturi, the flow rate on the inlet side of the splitventuri would include gradually reducing the pressure of the flow as itflows into the first portion of the split venturi and at the same timeincreasing the velocity of the flow. At the split or interface of thesplit venturi between the first portion and a second portion, the flowwould start to gradually increase in pressure while decreasing invelocity as it flows through the second portion of the split venturi tosome exit port. In some instances, the ambient conditions may be suchthat the conduit itself may provide a conduction path to adverse ambientconditions, such as freezing temperatures. In such instances, it may bebeneficial to split the conduit in the freezing area and create athermal barrier between at least the two portions of the conduit suchthat the energy is not lost to adverse ambient temperatures. At theinterface behind the first portion and second portion, a seal may beused. Such a seal could be adapted to seal the periphery of theinterface and in some instances seal diametrically, as will be discussedfurther. The diametrical seal may be linear or, in some fashion,curvilinear. In some embodiments, the conduit might not be rigid, atleast in parts. The conduit might include for instance a flexible tube.A proper location might be such that no interference of the seal betweenthe first and second portions might occur.

[0023] Another goal of the present invention is to provide a valve thatincludes a split venturi between the first and second portion where theportions are non-axisymmetric relative to a central axis. Heretofore,the typical venturi design has been concentric in that at any givencross section the outer periphery is equidistant from a central axis.The present invention abruptly departs from this standard practice byhaving a non-axisymmetric or eccentric venturi that is split in twosections. The two sections may be fluidly connected to one another suchas the fluid might flow from one into the other with little changeacross the interface. Furthermore, such a flow path may be semicircular.By departing from this standard practice of axisymmetric venturis, thepresent invention is better able to utilize its unique closing andopening capabilities. It is another objective of the present inventionto include a rotating internal elbow connected to at least one of theportions that rotates so that as the portion is rotated, the internalelbow can direct the flow into a valve outlet.

[0024] Another goal of the present invention is to include anaxially-rotated valve using a split venturi having a first and secondportion where at least one portion may be rotated by an axial rotatoroutside of the flow without substantial interference with flowefficiency. One objective of this goal is to provide an axially-rotatedvalve that is designed to provide streamlined flow (that is, avoidingflow separation and/or cavitation at full flow under a variety ofconditions).

[0025] Naturally, other objectives of the invention are disclosedthroughout other areas of the specification and claims. In addition, thegoals and objectives may apply either in dependent or independentfashion to a variety of other goals and objectives in a variety ofembodiments.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1a shows a graph of pressure drop as a function of flow ratetest results of the present invention compared to some commerciallyavailable axially-rotated valves to show some of the significantimprovements.

[0027]FIG. 1b shows a graph of measured loss coefficients as a functionof Reynolds number for the present invention compared to somecommercially available axially-rotated valves and other types of valves,again to show some of the significant improvements of the presentinvention.

[0028]FIG. 2 is a cross section of the present invention from a sideperspective in a fully-opened orientation.

[0029]FIG. 3 is a cross section of the present invention from a sideperspective in a fully-closed orientation.

[0030]FIG. 4 shows an end view of the first portion (8) in anon-axisymmetric eccentric embodiment shown in FIG. 3.

[0031]FIG. 5 shows an end view of the second portion (18) in anon-axisymmetric eccentric embodiment shown in FIG. 3.

[0032]FIG. 6 is an end view of a seal at an interface between a firstand second portion.

[0033]FIG. 7 is an end view of a seal at an interface between a firstand second portion as an alternative embodiment to FIG. 6.

V. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0034] As mentioned earlier, the present invention includes a variety ofcomponents that may be used in various combinations, depending on theapplication that needs to be addressed. This invention is intended toencompass a wide variety of embodiments of an axially-rotated valve. Inparticular, the invention is designed primarily to take advantage of lowfriction loss, high efficiency, high flow through an eccentric splitventuri of a particular and novel design and combine and modify asneeded for a variety of shapes, sizes and orientations, as will beexplained in more detail as the figures are described. Elements,functions and procedures that distinguish the present invention will benoted where appropriate.

[0035] As can be easily understood, the basic concepts of the presentinvention may be embodied in a variety of ways. It involves both methodsand devices to accomplish the appropriate method. In this patent, themethods are disclosed as part of the results shown to be achieved by thevarious devices described and as steps that are inherent to utilization.They are simply the natural result of utilizing the devices as intendedand described. In addition, while some devices are disclosed, it wouldbe understood that these not only accomplish certain methods, but alsocan be varied in many ways. Importantly, as to the foregoing, all thesefacets should be understood to be encompassed by this disclosure.

[0036]FIG. 2 shows a fully-opened eccentric split venturiaxially-rotated valve in a cross-section side view. Starting from theleft of the valve (2), a flow (4) enters the valve. The valve may have acentral axis (6) which for a typical valve may operate as a center lineof the valve. As the flow (4) enters the valve (2), the flow may firstencounter a first portion (8) having a first longitudinal axis (10) anda first flow path (12). The flow (4) may progress across an interface(14) along a first flow axis (11) in a transition flow zone (16) andinto a second portion (18). The second portion (18) may have its ownsecond flow axis (21), a second longitudinal axis (20), a second flowpath (22), and a diameter (24). As the flow continues, it may exitthrough an exit port (26). The exit port in some embodiments may includean internal elbow (28) to help direct the flow (4) into a valve outlet(30).

[0037] The first portion (8) may be a fixed sleeve inside the valve (2).By fixed, it is intended to mean that generally the first portionremains in a constant rotational orientation with respect to the valvein use. The first portion (8) may be removable from the valve or may bemore securely attached, such as being made integral to the valve,welding, brazing, adhesively attaching, compression fitting, and soforth as would be known to those skilled in the art. One possibility forthe first portion (8) is that it may be a cartridge assembly which maybe removable for maintenance or replacement purposes. As a cartridgeassembly, it may include cartridge seals (32) in a variety of places aswould be appropriate and known to those skilled in the art.

[0038] The first portion (8) may include an eccentric portion of a splitventuri. A typical venturi includes a smooth transition from a largediameter to a small diameter and then again to a large diameter. Thepresent valve uniquely uses a venturi that is split into at least twoportions. At the split, the interface (14) results in a transition flowzone (16) from a decreasing cross sectional area to an increasing crosssectional area. The first portion (8), working in conjunction with thesecond portion (18), to be described in more detail below, typicallywould have an eccentric split venturi so that by rotating the secondportion, a closure of the flow (4) may be had.

[0039] As the flow (4) continues along the first portion (8) and engagesthe split venturi (34), it encounters an inlet slope (36). The inletslope (36) may form a conical shape of uniform slope about the peripheryof the flow path with respect to the longitudinal axis in someembodiments. However, in the preferred embodiment, the slope may form aneccentric slope. By eccentric, it is meant to relate to a slope along alongitudinal perspective and may include such slopes as are shown inFIG. 2 where the flow-path may have different slopes about the peripheryof the flow path. This would include diverging the center of the flow(4) from the longitudinal axis (10) to the first flow axis (11).Similarly, an eccentric slope could diverge the flow path through secondportion (18) along a central second flow axis (21) then to secondlongitudinal axis (20). The first flow axis (11) and second flow axis(21) are central axes of the flow paths through the first portion (8)and second portion (18) and may vary in relative height with respect tothe central axis (6) as the flow turns up the first slope (36) and intothe split venturi (34) and then down slope (40). (The first longitudinalaxis (10) and the second longitudinal axis (20) in the preferredembodiment may coincide with the central axis (6) through the valve.) Asthe flow continues toward the transition flow zone (16), the slope maydecrease. In the preferred embodiment, the slope may be a zero slope,that is, neither decreasing nor increasing in cross sectional area atthe interface (14) in the transition flow zone (16). In the preferredembodiment, the slope on the first portion (8) appears to be lesscritical than the slope on the second portion (18). Thus, the slopes maybe different. The slope on the first portion may be approximately 5-15degrees, although other angles could be suitable, and for someembodiments a slope of 9-11 degrees may be appropriate.

[0040] In addition to the eccentricity of the split venturi, the crosssectional area across the flow path shown more accurately in FIG. 3 maybe non-axisymmetric, such as approximately semicircular. Bysemicircular, it is not meant to be restricted to an exact 180° of aperfect circle; it can have a variety of shapes that could includeapproximately one-half of a flow area of the flow path of the flow (4)less any requirements for a diametrical seal such is shown in FIGS. 6and 7. The non-axisymmetric aspect of FIG. 4 relates to the crosssectional flow area. For instance, the first flow axis (11) is shown ata center of the cross sectional area, where the center represents amidpoint of the distances to the periphery. In other words, the pointsof the periphery of the flow area are not equidistant from the firstflow axis (11). Similarly, in FIG. 5, the second portion (18) may have acorrespondingly shaped cross sectional flow area about a second flowaxis (21) to align with the cross sectional area and flow path with thefirst portion (8).

[0041] Returning to FIG. 2, as the flow flows across the interface (14)in the transition flow zone (16), the flow enters the second portion(18). As would be known to those skilled in the art, in the transitionflow zone, the pressure exerted by the flow may be minimal due to thecharacteristics of the split venturi. However in a closed position(shown in more detail in FIG. 3), the static pressure of the substancesuch as a fluid may exert pressure at the interface (14) between thefirst portion (8) and the second portion (18). If desired, a first seal(38) may be provided in the interface (14).

[0042] As a flow flows through the second portion (18), the flow isgradually increased in pressure and decreased in velocity. Test resultsshow that for optimal flow characteristics, and in order to obtain lessfriction loss and higher flow rates, the slope (40) of the secondportion (18) may be more important than the first slope (36). The slope(40) may be inclined at an angle of approximately 5-15 degrees, and inthe preferred embodiment, approximately 7-8 degrees. The length todiameter ratio may be at least 6:1, and preferably at least 8:1. Inother words, the length of the second portion (18) in the preferredembodiment may be at least six times longer than the diameter (24) ofthe second portion (18) for optimal flow characteristics in reducingpressure drop and increasing flow rate for a given pressure anddiameter. It has been observed that such a slope may avoid, under manyconditions, the flow separation and/or cavitation of the fluid as itflows from the first portion into the second portion and through thesecond portion. Cavitation and flow separation will be discussed in moredetail below.

[0043] At some point along the second portion (18), the flow (4) mayexit through an exit port (26). To assist in reducing the pressure dropfrom the flow, a smooth transition may be preferable. A smoothtransition in exit port (26) may include an internal elbow (28). Theinternal elbow may be fluidicly connected or may be integral to thesecond portion (18). In some embodiments, the integral elbow may befluidicly connected to the first portion (8). As the flow exits throughthe exit port and perhaps through the internal elbow (28), the flow maybe directed through a valve outlet (30). In some embodiments, it may beuseful to have an exit port seal (42) located at the exit port interface(44) between the exit port (26) and valve outlet (30). This exit portseal (42) might further enhance any sealing capabilities such as mightbe needed for a particular application. The valve outlet (30) couldinclude typical hose connections, hose bibs, and so forth as would havecommonly known to those in the industry. To further assist the flow outof the exit port region and through the valve outlet, the internal elbowmay be configured (such as be casting, molding, machining, and so forth)to a more circular shape (from the preferred embodiment's semicircularcross section) so that the flow may proceed into the typically circularvalve outlet shape such as a hose bibb, known to those in the art.

[0044] In the preferred embodiment, a valve actuator (48) may act in anaxial direction to rotate the second portion (18) where the secondportion (18) could be described as a rotatable sleeve. As discussedearlier, one of the pressure losses (up to approximately 20% of thepressure loss) of axially-rotated valves has included the presence of avalve stem within the flow path. As can be seen in FIG. 2, the valveactuator (48), operating in an axial fashion, is outside the flow path.The valve actuator in FIG. 2 may be directly connected and may beintegral to the rotatable sleeve functioning as a second portion (18).Thus, the valve actuator (48) may cause no or little pressure losscompared to a valve actuator located within the flow path of the flow(4) of typical axially rotated valves such as disclosed in U.S. Pat. No.4,532,954. To operate the valve, the valve actuator might only be turnedapproximately one-half turn from a filly-opened to a fully-closedposition. As would be known to those skilled in the art, a packing orother sealing member (46) could be used to seal the valve from internalleakage along the area of the valve actuator (48).

[0045] Similar to the first portion (8) being included as a cartridge,the second portion (18) may similarly be included as a cartridge. Thiscould be especially suitable if the first portion (8) were fixed inposition in a more permanent mode. Thus if replacement and maintenancewere desired, the cartridge assembly could include the valve actuator,internal elbow, exit port and other parts of the second portion (18) andperhaps even the first seal (38) so that quick and easy maintenancecould be accomplished.

[0046] To aid in the sealing of the second portion (18) with the firstportion (8), an axial compression member (50) may be included. Forinstance, in the preferred embodiment, the axial compression member (50)may be a spring or a Bellville washer, as would be known to those withskill in the art, or other biasing elements.

[0047] A further aspect of the present invention may include theprovision of a purge valve (52). The purge valve (52) may include apurge plug (54), a purge biasing member (56), and a purge seat (58). Apurge valve actuator (60), for instance, located on a second portion(18), when rotated to an appropriate position, could push the purge plug(54) against the purge seat (58) and seal the purge port when a flowcondition existed. When a purge valve actuator was rotated to an offsetposition, the purge biasing member (56) could bias the purge plug (54)off the purge seat (58) and allow drainage of any appropriate spaces.

[0048] In some instances in adverse ambient conditions, such as freezingweather, it may be preferable to provide a thermal break in the conduit.The conduit (62) may be an external portion of the valve body.Typically, this may include some metallic substance such as brass,steel, copper, bronze, and so forth as would be known to those skilledin the art. Because metal typically is a conductor, as opposed to aninsulator, the exposure of the conduit surfaces to adverse ambientconditions may encourage freezing at the valve. In such instances, itmay be preferable to provide a thermal break (64) and divide the conduitinto at least a first conduit section (66) and a second conduit section(68). The thermal break may include a variety of substances such asnonconductive plastic, insulation, or any other elements such as wouldretard the adverse ambient condition from being transmitted down theconduit. One of the aspects of the present valve is that it may allowthe location of the thermal break in a variety of locations.

[0049]FIG. 3 shows the valve in a fully-closed position. The firstportion (8) has remained in position; however, the second portion (18)has been rotated, in this instance, approximately 180° about itslongitudinal axis. In the preferred embodiment, the longitudinal axisoverlaps the central axis (6). However, it is possible that otherembodiments could vary the alignment. It is envisioned that in mostinstances, the longitudinal axis will at least be substantially parallelto the central axis (6). By parallel, it is meant to include unlessotherwise stated substantially parallel up to an approximately 30°deviation.

[0050] As can be shown in FIG. 3, the internal elbow may be rotated intoa nonaligned position with respect to the valve outlet (30). Asdescribed in FIG. 2, there may be a seal between the internal elbow (28)at the exit port interface (44) and the valve outlet (30). Thus, itmight even be, in some embodiments, that the first seal (38) might notbe present. Also, as shown in FIG. 3, the valve actuator (48) has simplybeen rotated approximately 180° or a one-half turn rotation to effectthe restriction of the flow (4). Such a quick shut off or restrictionmay be useful in many instances. Also shown in FIG. 3 is the purge valveactuator (60) in a rotated position away from the purge valve (52) wherethe purge plug (54) has been biased away from the purge seat (58).

[0051] As mentioned earlier, FIG. 2 and FIG. 3 show a first seal (38).FIGS. 3, 6, and 7 show the peripheral seal (70) and the diametrical seal(72) (as a linear diametrical seal (76) and a curvilinear diametricalseal (82)). As the second portion (18) and first portion (8) are biasedtoward each other, the first seal (38) acting through the peripheralseal (70) and the diametrical seal (72) may restrict leakage of the flow(4) from the first portion (8) into the second portion (18). It may alsorestrict leakage into the cavity (74) between the conduit (62) and thefirst and second portions.

[0052] This term seal is intended as a functional term. Thus, a separatemember may not be necessary. For instance, some test results show thatsome materials may inherently seal without the necessity of a separateseal. For instance, Delrin™ is generally considered a hard plastic, andyet appears to be soft enough (with a durometer of approximately 80)such that a seal may be effected functionally. Such a seal may beenhanced by the axial compression member (50) pressing the first portion(8) and second portion (18) toward each other. Another advantage ofDelrin™ appears to be that it is a self lubricating plastic. In otherwords, it may resist scoring as it is rotated back and forth. Othermaterials that may offer possibilities are other polymers, ceramics,various metals, and so forth. The appropriate material may be varieddepending upon the particular application. For instance, it is knownthat softer materials resist erosion of abrasive materials better thanharder materials. Thus, those with a lower durometer, may be moresuitable in some instances, as would be known to those with skill in theart. Furthermore, while the conduit (62) has been described generally ina metallic fashion, it is entirely feasible to have a conduit of othermaterials such as plastics and so forth. In some instances, the conduitcould even be made of a soft flexible material, at least in a portion.

[0053] Also, as would be known to those with skill in the art, anin-line spool perhaps with two seals between the first portion (8) andthe second portion (18) could be useful in some embodiments. Naturally,other embodiments could be used. In some instances, it may not even beimportant to have a seal between the first and second portion. Themarket place and commercial concerns might dictate the particularvariations.

[0054] The valve rotator (48) has been shown to be connected to thesecond portion (18). Naturally, other embodiments are possible. Forinstance, because the flow between the first and second portions may besealed from the cavity (74), it is possible that side mounted valveactuators that might extend through the conduit (62) could rotate forinstance the second portion (18). Such a valve rotator could still beconsidered an axial rotator because it could indeed rotate for instancethe second portion (18) along the second longitudinal axis (20) and evenbe outside the flow path of the flow (4).

[0055]FIG. 6 shows an end view of the first seal (38). As describedabove, the first seal (38) could functionally be incorporated into theparticular material used as the first portion (8) or the second portion(18) or both. The first seal (38) might include a peripheral seal (70).The peripheral seal as shown in FIGS. 2 and 3 might seal the outerperimeter of the first and second portions. The first seal (38) mightalso include a diametrical seal (72), shown in FIG. 6 more particularlyas a somewhat straight linear diametrical seal (76). As shown in FIG. 2and FIG. 3, the diametrical seal (72) might be located at the juncturewhere the first portion and second portion are rotated with respect toeach other along the respective longitudinal axis. The thickness andwidth and resulting cross sectional area of the diametrical seal mightbe structured to contain the full pressure of the flow (4) when thesecond portion (18) is rotated to a restricting position, shown in FIG.3. This typically would relate to the strength of materials, pressure,diameter, and other factors known to those with skill in the art. Bydiametrical, the term is meant to include a variety of cross sectionssuch as circular, eccentrical, rectangular, square, and other crosssectional areas. In the test results, it appears that the flow area (78)of FIG. 4 might correspond to the open area (80) of the seal in FIG. 6such that the flow area (78) might not be less than approximately 40% ofthe flow path in the preferred embodiment compared to the flow area, forinstance, at the diameter (24). (The various percentages and membersdescribed in this patent are approximate and may be varied according tothe particular conditions and flows desired.) The linear diametricalseal (76) as shown in FIG. 6 may be substantially planar to theperipheral seal (70).

[0056]FIG. 7 shows an alternative embodiment of the diametrical seal(72). While FIG. 6 shows a somewhat straight linear diametrical seal,the present invention is not so restricted. It may include a variety ofseals in a diametrical fashion. Such a seal could include thecurvilinear diametrical seal (82) shown in FIG. 7. In most instances,where a high flow was desired, the minimal restriction would bepreferred. Thus, the cross sectional area of the diametrical seals wouldpreferably be minimized to effect the higher flow rates.

[0057] It is a goal of the present invention to minimize pressure dropthrough the valve, even at high flow rates. Increased pressure drop maybe caused by turbulent flow, flow separation, and/or cavitation. Flow inpiping components, including valves, is typically characterized by theloss coefficient, which is proportional to the pressure drop through thecomponent and inversely proportional to the fluid density and inverselyproportional to the fluid velocity squared. The flow coefficient may berepresented by the formula: K_(L)=ΔP/½ρV² where K_(L) represents theflow coefficient, ΔP represents the pressure drop, ρ represents thedensity of the fluid, and V represents the average velocity of the fluidin the nominal pipe.

[0058] By manufacturing and using a slope (40) for the eccentric splitventuri such as described above, and even perhaps by using an internalelbow (28), the loss coefficient can be minimized. (Obviously, othersteps, in addition to and in lieu of, may be taken that could result ina lower loss coefficient.) This may result in a valve with a lowerpressure drop even at high flow rates. Test results have shown that theloss coefficient of this particular invention is less than those of anyknown axially-rotated valve. The loss coefficient for this type of valvemay range in the area of 4 or less. (Obviously, this value is intendedto cover ranges of approximately 4 and is not intended to applyspecifically to 4.000. The same is true for the other values expressedin this application.) For the preferred embodiment, the range may be 3.5or less. By comparison, the loss coefficient of other types ofaxially-rotated valves such as that disclosed in the '954 referencedescribed above has been measured to be 15 at comparable flowconditions. The present invention has even a lower loss coefficient thanother types of axially actuated valves used in the marketplace. As wouldbe known to those in the art, the loss coefficient may be fairlyconstant across a range of flows and, thus, the improvements of thepresent invention may apply broadly.

[0059] Another aspect of the invention relates to flow separation.Separation may occur when there is flow over or past an insufficientlystreamlined, blunt object. When the flow rate becomes sufficientlylarge, the streamlines of the flow past such objects no longer followthe boundaries of the flow. Indeed, flow may actually reverse in theseparated region, which actually decreases the effective cross-sectionarea of a closed conduit. (See, e.g., Munson, Bruce, Young, Donald,Okiishi, Theodore, Fundamentals of Fluid Mechanics, p. 558 (John Wiley &Sons 2d. ed. 1994)). Thus, flow separation leads to higher pressuredrop, resulting in an overall higher loss coefficient. This inventionhas been designed to minimize or eliminate flow separation.

[0060] It is also a goal of the present invention to includenoncavitational flow in some embodiments. The embodiments described,especially in FIGS. 2 and 3, may assist in this goal. Generally, thetransition flow zone (16) appears to be the more important area toassist in avoiding cavitation. The cavitation occurs, as would be knownto those with skill in the art, when the flow characteristics establisha pressure gradient that exceeds the vapor pressure for a given fluid ata given temperature. By manufacturing and using a transition flow zonefor the eccentric split venturi described above, cavitation may beavoided in many instances at full flow at least in this area of thevalve. Generally, in the preferred embodiment, this area should be aslarge as possible in keeping with the goals and objectives of thepresent invention to lessen the risk of cavitation, where appropriate.

[0061] In some embodiments, the flow may also be somewhat laminar. Whilethere may be boundary layer flow that on a microscopic scale might notbe laminar, as would be known to those with skill in the art, thelaminar flow on a macroscopic scale may be realized to the presentinvention. Laminar flow is one in which the fluid flows in layers. Theremay be small macroscopic mixing of adjacent fluid layers. The laminarflow may be seen, for instance, by introducing a dye somewhere in thestream to develop a stream line which flows through a portion of thevalve without substantial deterioration. In such instances, the laminarflow may point to the smoothness of the flow with the resulting lowerfriction loss and higher flow rates for a given size of valve at a givenpressure. As would be known to those with skill in the art, the laminarflow characteristics can be related to the Reynolds Number. Thus, bychoosing an appropriate curve, which may include the type described forslope (40) above for the eccentric split venturi, the pipe diameter(that is a cross sectional area at any given point in the venturi) andthe average flow velocity may be carefully controlled so that anappropriate Reynolds Number may not be exceeded and the flow is somewhatlaminar in some portion of the split venturi and may include asubstantial percentage of the second portion (18). (The discussion offlow separation, cavitation, and laminar aspects does not necessarilyinclude the flow through the exit port and internal elbow.)

[0062] Regarding the throttling characteristics, it may be seen that asthe first portion (8) and second portion (18) are rotated using, in thepreferred embodiment, the semicircular eccentric split venturi, anunusually small area of the flow path (78) of the first portion maycorrespond to an unusually small area of the flow path of the secondportion as the valve is closed. In other words, a small portion of thediametrical “pie” may be used for small variations in controlling theflow.

[0063] Each of these valve embodiments could include various facets ofthe present invention. Some may include flow separation and/orcavitation flow avoidance elements, while others may not include suchelements. Some may include varieties of seals and others not includesuch seals, while still others may include certain optimal flow lengthswhile others may be less concerned about the optimal flow length. Themarket place and manufacturing concerns may dictate the appropriateembodiments for the present invention.

[0064] The foregoing discussion and the claims that follow describe onlythe preferred embodiments of the present invention. Particularly withrespect to the claims, it should be understood that a number of changesmay be made without departing from the essence of the present invention.In this regard, it is intended that such changes, to the extent thatthey substantially achieve the same results in substantially the sameway, will still fall within the scope of the present invention.

[0065] Although the methods related to the system are being included invarious detail, only initial claims directed toward the valve have beenincluded. Naturally, those claims could have some application to thevarious other methods and apparatus claimed throughout the patent. Thedisclosure of the apparatus or method context is sufficient to supportthe full scope of methods and apparatus claims with, for instance, theaxially-rotated valves, purge ports, non-axisymmetric venturis, internalelbows, unseparated, non cavitation, and laminar flow designs, and soforth. While these may be added to explicitly include such details, theexisting claims may be construed to encompass each of the other generalaspects. Without limitation, the present disclosure should be construedto encompass subclaims, some of those presented in an apparatus ormethod context as described above for each of the other general aspects.In addition, to the extent any revisions utilize the essence of theinvention, each would naturally fall within the breadth of protectionencompassed by this patent. This is particularly true for the presentinvention since its basic concepts and understandings may be broadlyapplied.

[0066] As mentioned earlier, this invention can be embodied in a varietyof ways. In addition, each of the various elements of the invention andclaims may also be achieved in a variety of manners. This disclosureshould be understood to encompass each such variation, be it a variationof an embodiment of any apparatus embodiment, a method or processembodiment, or even merely a variation of any element of these.Particularly, it should be understood that as the disclosure relates toelements of the invention, the words for each element may be expressedby equivalent apparatus terms or method terms—even if only the functionor result is the same. Such equivalent, broader, or even more genericterms should be considered to be encompassed in the description of eachelement or action. Such terms can be substituted where desired to makeexplicit the implicitly broad coverage to which this invention isentitled. As but one example, it should be understood that all actionmay be expressed as a means for taking that action or as an elementwhich causes that action. Similarly, each physical element disclosedshould be understood to encompass a disclosure of the action which thatphysical element facilitates. Regarding this last aspect, the disclosureof a “seal” should be understood to encompass disclosure of the act of“sealing”—whether explicitly discussed or not—and, conversely, werethere only disclosure of the act of “sealing”, such a disclosure shouldbe understood to encompass disclosure of a “seal.” Such changes andalternative terms are to be understood to be explicitly included in thedescription.

[0067] It is simply not practical to describe in the claims all thepossible embodiments to the present invention which may be accomplishedgenerally in keeping with the goals and objects of the present inventionand this disclosure and which may include separately or collectivelysuch aspects as axially-rotated valves, eccentric split venturis,internal elbows, valve actuators located outside the flow path, andother aspects of the present invention. While these may be added toexplicitly include such details, the existing claims should be construedto encompass such aspects. To the extent the methods claimed in thepresent invention are not further discussed, they are natural outgrowthsof the system or apparatus claims. Therefore, separate and furtherdiscussion of the methods are deemed unnecessary as they otherwise claimsteps that are implicit in the use and manufacture of the system or theapparatus claims. Furthermore, the steps are organized in a more logicalfashion; however, other sequences can and do occur. Therefore, themethod claims should not be construed to include only the order of thesequence and steps presented.

[0068] Furthermore, any references mentioned in the application for thispatent as well as all references listed in any information disclosureoriginally filed with the application are hereby incorporated byreference. However, to the extent statements might be consideredinconsistent with the patenting of this/these invention(s), suchstatements are expressly not to be considered as made by theapplicant(s).

We claim:
 1. An axially-rotated split venturi valve comprising: a. atleast one rotatable sleeve; b. a fixed position sleeve fluidiclyconnected to said rotatable sleeve; c. an axial eccentric split venturihaving a first portion and a second portion wherein said first portionis located inside said fixed sleeve and said second portion is locatedinside said rotatable sleeve; d. an exit port fluidicly connected tosaid rotatable sleeve; e. a conduit in which said rotatable sleeve andsaid fixed position sleeve are located having a flow path; f. aninterface between said rotatable sleeve and said fixed sleeve; g. afirst seal between said rotatable sleeve and said fixed sleeve at saidinterface wherein said rotatable sleeve, said fixed position sleeve,said axial eccentric split venturi, said exit port, said conduit, saidinterface and said first seal comprise an axially-rotated split venturivalve.
 2. An axially-rotated split venturi valve as described in claim 1further comprising an axial rotator outside of said flow path adapted torotate said rotatable sleeve without substantial engagement of saidaxial rotator to said rotatable sleeve within said flow path.
 3. Anaxially-rotated split venturi valve as described in claim 1 wherein saidaxial eccentric split venturi comprises a semicircular eccentric splitventuri primarily in the proximity of said interface.
 4. Anaxially-rotated split venturi valve as described in claim 1 furthercomprising an axial compression member adapted to bias said rotatablesleeve and said fixed position sleeve toward each other.
 5. Anaxially-rotated split venturi valve as described in claim 1 wherein saidrotatable sleeve is adapted to substantially avoid cavitation throughoutsaid rotatable sleeve of said valve beginning at said interface.
 6. Anaxially-rotated split venturi valve as described in claim 1 wherein saidvalve is adapted to establish a loss coefficient of 4 or less.
 7. Anaxially-rotated split venturi valve as described in claim 1 furthercomprising a separation in said conduit adapted to create a thermallyinsulative barrier in said conduit at said separation.
 8. Anaxially-rotated split venturi valve as described in claim 1 wherein saidfirst seal comprises an outer periphery seal and a diametrical seal insubstantially the same plane as said outer periphery seal.
 9. Anaxially-rotated split venturi valve as described in claim 1 wherein saidvalve comprises a freeze resistant, axially-rotated split venturi valvecomprising a first seal at an interface between said first and secondportions located a freeze distance away from freezing conditions.
 10. Anaxially-rotated split venturi valve as described in claim 1 wherein saidrotatable sleeve comprises a length sufficient to substantiallyeliminate flow separation through said rotatable sleeve.
 11. Anaxially-rotated split venturi valve as described in claim 1 wherein saidrotatable sleeve is longer than said fixed position sleeve.
 12. Anaxially-rotated split venturi valve as described in claim 1 furthercomprising an exit port fluidicly connected to at least one of saidsleeves and further comprising an internal elbow.
 13. An axially-rotatedsplit venturi valve as described in claim 12 further comprising an exitport seal at an exit port interface between said exit port and a valveoutlet fluidicly connected to said valve.
 14. An axially-rotated splitventuri valve as described in claim 1 further comprising a cartridgeassembly adapted for insertion in said conduit comprising at least oneof said sleeves.
 15. An axially-rotated split venturi valve as describedin claim 14 further comprising a cartridge seal assembly around saidcartridge assembly adapted to seal cartridge assembly in said conduit.16. An axially-rotated split venturi valve as described in claim 1wherein said first seal comprises a curvilinear diametrical seal.
 17. Anaxially-rotated split venturi valve as described in claim 1 wherein saidconduit comprises a flexible tube.
 18. An axially-rotated split venturivalve as described in claim 1 wherein said rotatable sleeve incooperation with said fixed position sleeve is adapted to be fullyopened and fully closed in one half complete rotation.
 19. Anaxially-rotated split venturi valve as described in claim 1 furthercomprising a purge port assembly adapted to open and allow drainage ofsaid valve when said valve is in at least a partially closed position.20. A method of improving flow from an axially-rotated valve using asplit venturi comprising: a. flowing through a flow path having apressure and velocity; b. entering a first portion of an eccentric splitventuri; c. gradually reducing said pressure of said flow whileincreasing said velocity of said flow through said first portion of saideccentric split venturi; d. flowing across an interface of said splitventuri between said first portion and a second portion; e. graduallyincreasing said pressure of said flow while decreasing said velocity ofsaid flow through said second portion of said eccentric split venturi;f. exiting said second portion through an exit port fluidicly connectedto said second portion; g. axially rotating said second portion of saidsplit venturi to at least a partially closed position; h. at leastpartially restricting said flow from flowing through said valve at saidinterface; i. rotating said second portion of said split venturi to atleast a partially open position; j. allowing said flowing of said fluidthrough said axially-rotated valve.
 21. A method of improving flow froman axially-rotated valve as described in claim 20 wherein said axiallyrotating said second portion comprises axially rotating said secondportion with an axial rotator outside of said flow path withoutsubstantial interference with flow efficiency.
 22. A method of improvingflow from an axially-rotated valve as described in claim 20 whereinflowing across an interface comprises flowing through a semicirculareccentric flow path.
 23. A method of improving flow from anaxially-rotated valve as described in claim 20 further comprisingassisting said sealed interface with an axial pressure element.
 24. Amethod of improving flow from an axially-rotated valve as described inclaim 20 wherein gradually increasing said pressure of said flow whiledecreasing said velocity of said flow comprises avoiding cavitation ofsaid flow.
 25. A method of improving flow from an axially-rotated valveas described in claim 20 further comprising establishing a losscoefficient of 4 or less through said axially-rotated valve.
 26. Amethod of improving flow from an axially-rotated valve as described inclaim 20 wherein flowing through a flow path comprises flowing through athermally conductive conduit and further comprising: a. providing aseparation in said thermally conductive conduit in a freezing zonewherein said separation creates a first conduit section and a secondconduit section of said conduit; and b. thermally breaking said firstconduit section from said second conduit section in a freeze zone.
 27. Amethod of improving flow from an axially-rotated valve as described inclaim 20 further comprising sealing at said interface comprising: a.sealing about a periphery of said interface between said portions; b.sealing across a diametrical portion of said interface in the same planeas said sealing about said periphery.
 28. A method of improving flowfrom an axially-rotated valve as described in claim 20 furthercomprising resisting the freezing of said valve.
 29. A method ofimproving flow from an axially-rotated valve as described in claim 20further comprising flowing through a length of said second portionsufficient to substantially eliminate flow separation through saidsecond portion.
 30. A method of improving flow from an axially-rotatedvalve as described in claim 20 further comprising flowing through alonger flow path in said second portion than said first portion.
 31. Amethod of improving flow from an axially-rotated valve as described inclaim 20 further comprising exiting said second portion through an exitport comprising exiting through an internal elbow to a valve outletfluidicly connected to said valve.
 32. A method of improving flow froman axially-rotated valve as described in claim 31 further comprisingsealing at said exit port between said internal elbow and said valveoutlet.
 33. A method of improving flow from an axially-rotated valve asdescribed in claim 20 wherein said flowing through said flow pathcomprises flowing through a conduit and further comprising inserting atleast one of said portions as a cartridge assembly in said conduit. 34.A method of improving flow from an axially-rotated valve as described inclaim 33 further comprising sealing said cartridge assembly in saidconduit.
 35. A method of improving flow from an axially-rotated valve asdescribed in claim 20 further comprising sealing said second portionwith said first portion with a curvilinear diametrical seal at saidinterface.
 36. A method of improving flow from an axially-rotated valveas described in claim 20 wherein said conduit comprises a flexible tube.37. A method of improving flow from an axially-rotated valve asdescribed in claim 20 wherein axially rotating from a closed position toan open position comprises axially rotating said second portionapproximately one half turn.
 38. A method of improving flow from anaxially-rotated valve as described in claim 20 further comprisingpurging said axially-rotated valve in at least a partially closedposition.
 39. A method of providing improved flow from a valve using asplit venturi comprising: a. flowing a fluid through a flow path with apressure and velocity along a central axis; b. gradually reducing saidpressure of said fluid while increasing said velocity of said fluidthrough a first portion of a split venturi wherein said first portion isnon-axisymmetric relative to said central axis; c. gradually increasingsaid pressure of said fluid while decreasing said velocity of said fluidthrough a second portion of said split venturi wherein said secondportion is non-axisymmetric relative to said central axis; d. rotatingat least one of said portions of said split venturi to at least apartially closed position; e. at least partially restricting said fluidfrom flowing through said valve; f. rotating at least one of saidportions of said split venturi to at least a partially open position; g.allowing said flowing of said fluid.
 40. A method of providing improvedflow from a valve as described in claim 39 wherein flowing said fluidcomprises flowing through a semicircular eccentric non-axisymmetric flowpath.
 41. A method of providing improved flow from a valve as describedin claim 39 wherein rotating at least one of said portions comprisesaxially rotating said portion about a longitudinal axis parallel to saidcentral axis.
 42. A method of providing improved flow from a valve asdescribed in claim 39 wherein rotating at least one of said portions ofsaid split venturi to at least a partially closed position furthercomprises axially rotating said second portion relative to said firstportion and controlling flowing through said relative rotation.
 43. Amethod of providing improved flow from a valve as described in claim 39wherein rotating comprises axially rotating while maintaining a fixedlongitudinal position of said rotated portion.
 44. A method of providingimproved flow from a valve as described in claim 39 further comprisingat least partially sealing at an interface between said first and secondportions.
 45. A method of providing improved flow from a valve asdescribed in claim 39 further comprising rotating a second portionlonger than first portion.
 46. A method of providing improved flow froma valve as described in claim 39 wherein said rotating at least one ofsaid portions comprises rotating an internal elbow connected to saidportion.
 47. A method of providing improved flow from a valve asdescribed in claim 39 further comprising exiting said second portionthrough an exit port and sealing said exit port with an exit port sealat an exit port interface between said exit port and a valve outletfluidicly connected to said valve.
 48. A method of providing improvedflow from a valve as described in claim 39 wherein rotating at least oneof said portions comprises axially rotating said portion with an axialrotator outside of said flow path without substantial interference withflow efficiency.
 49. A method of providing improved flow from a valve asdescribed in claim 39 wherein said flowing said fluid through said flowpath comprises flowing through a conduit and further comprisinginserting at least one of said portions as a cartridge assembly in saidconduit.
 50. A method of providing improved flow from a valve asdescribed in claim 39 further comprising sealing at an interface betweensaid portions and assisting said interface with an axial pressureelement.
 51. A method of providing improved flow from a valve asdescribed in claim 39 further comprising flowing through a lengthsufficient to substantially eliminate flow separation through saidsecond portion.
 52. A method of providing improved flow from a valve asdescribed in claim 39 wherein flowing said fluid comprises flowingthrough a thermally conductive conduit and further comprising: a.providing a separation in said thermally conductive conduit in afreezing zone wherein said separation creates a first conduit sectionand a second conduit section of said conduit; and b. thermally breakingsaid first conduit section from said second conduit section in a freezezone.
 53. A method of providing improved flow from a valve as describedin claim 39 wherein gradually increasing said pressure of said flowwhile decreasing said velocity of said flow comprises avoidingcavitation of said fluid.
 54. A method of providing improved flow from avalve as described in claim 39 further comprising establishing a losscoefficient of 4 or less through said valve.
 55. A method of providingimproved flow from a valve as described in claim 39 further comprisingresisting the freezing of said valve by sealing at said interface afreeze distance away from freezing conditions.
 56. A split venturi valvecomprising: a. a conduit having a central axis and a flow path; b. afirst portion of a split venturi wherein at least a part of said firstportion is non-axisymmetric relative to said central axis; c. a secondportion of a split venturi wherein at least a part of said secondportion is non-axisymmetric relative to said central axis.
 57. A splitventuri valve as described in claim 56 wherein said portions of saidsplit venturi comprise an eccentric flow surface.
 58. A split venturivalve as described in claim 56 wherein said part of said first andsecond portion of said split venturi that is non-axisymmetric comprisesan eccentric semicircle.
 59. A split venturi valve as described in claim56 wherein said second portion comprises a rotatable second portionrelative to said first portion adapted to control a flow through saidconduit.
 60. A split venturi valve as described in claim 56 furthercomprising a first seal located between said first and second portionsin a transition flow zone.
 61. A split venturi valve as described inclaim 56 further comprising an internal elbow connected to one of saidportions.
 62. A split venturi valve as described in claim 56 furthercomprising an exit port connected to one of said portions and an exitport seal at an exit port interface between said exit port and a valveoutlet fluidicly connected to said valve.
 63. A split venturi valve asdescribed in claim 56 wherein said valve comprises an axially-rotatedvalve.
 64. A split venturi valve as described in claim 56 furthercomprising an axial rotator outside of said flow path adapted to rotateat least one of said portions without substantial engagement of saidportion within said flow path.
 65. A split venturi valve as described inclaim 56 further comprising a cartridge assembly adapted for insertionin said conduit comprising at least one of said portions.
 66. A splitventuri valve as described in claim 56 further comprising an axialcompression member adapted to bias said portions toward each other. 67.A split venturi valve as described in claim 56 wherein at least one ofsaid portions comprises a length sufficient to substantially eliminateflow separation through said portion.
 68. A split venturi valve asdescribed in claim 56 wherein said second portion is longer than saidfirst portion.
 69. A split venturi valve as described in claim 56further comprising a separation in said conduit adapted to create athermally insulative barrier in said conduit at said separation.
 70. Asplit venturi valve as described in claim 56 wherein at least one ofsaid portions of said valve is adapted to substantially preventcavitation throughout said portion beginning at an interface betweensaid first and second portions.
 71. A split venturi valve as describedin claim 56 wherein said valve is adapted to establish a losscoefficient of 4 or less.
 72. A split venturi valve as described inclaim 56 wherein said valve comprises a freeze resistant,axially-rotated valve comprising a first seal at an interface betweensaid first and second portions located a freeze distance away fromfreezing conditions.
 73. A method of providing improved flow from avalve using a split venturi comprising: a. establishing a flow through aflow path in at least a portion of an axially-rotated valve having acentral axis; b. controlling said flow between a first and secondportion of a split venturi wherein said portions are fluidicly connectedto said valve; c. axially rotating at least one of said portions of saidsplit venturi to a rotated position about a longitudinal axis parallelto said central axis to at least a partially closed position; d. atleast partially restricting said flow; e. axially rotating said rotatedportion of said split venturi about said longitudinal axis to at least apartially open position; f. continuing said flow through said valvewherein axially rotating said portions of said split venturi comprisesaxially rotating said portion with an axial rotator outside of said flowwithout substantial interference with flow efficiency.
 74. A method ofproviding improved flow from a valve as described in claim 73 furthercomprising interfering with less than 20% of a flow efficiency throughsaid flow path by said axial rotator.
 75. A method of providing improvedflow from a valve as described in claim 73 wherein controlling said flowfurther comprises flowing through an eccentric split venturi.
 76. Amethod of providing improved flow from a valve as described in claim 75wherein flowing through said eccentric split venturi comprises flowingthrough a semicircular eccentric split venturi.
 77. A method ofproviding improved flow from a valve as described in claim 73 whereinaxially rotating said rotated portion of said split venturi comprisesaxially rotating to align with the other said portion of said splitventuri for full flow.
 78. A method of providing improved flow from avalve as described in claim 73 wherein flowing said fluid through a flowpath comprises flowing with a pressure and velocity and furthercomprising: a. gradually reducing said pressure of said fluid whileincreasing said velocity of said fluid through said first portion ofsaid split venturi; b. gradually increasing said pressure of said fluidwhile decreasing said velocity of said fluid through said second portionof said split venturi; and c. avoiding substantial flow separation ofsaid fluid in at least said second portion.
 79. A method of providingimproved flow from a valve as described in claim 73 further comprisingestablishing a loss coefficient of 4 or less through said valve.
 80. Amethod of providing improved flow from a valve as described in claim 73further comprising sealing at an interface between said portionscomprising: a sealing about a periphery of said interface between saidportions; b. sealing across a diametrical portion of said interface inthe same plane as said sealing about said periphery.
 81. A method ofproviding improved flow from a valve as described in claim 73 furthercomprising exiting one of said portions through an exit port comprisingexiting through an internal elbow to a valve outlet fluidicly connectedto said valve.
 82. A method of providing improved flow from a valve asdescribed in claim 81 further comprising sealing at said exit portbetween said internal elbow and said valve outlet.
 83. A method ofproviding improved flow from a valve as described in claim 73 whereinsaid flowing through said flow path comprises flowing through a conduitand further comprising inserting at least one of said portions as acartridge assembly in said conduit.
 84. A method of providing improvedflow from a valve as described in claim 83 further comprising sealingsaid cartridge assembly in said conduit.
 85. A method of providingimproved flow from a valve as described in claim 73 further comprisingsealing at an interface between said portions and resisting the freezingof said valve by sealing at said interface a freeze distance away fromfreezing conditions.
 86. A split venturi valve comprising: a. anaxially-rotated valve having a central axis and a flow path; b. a firstand second portion of a split venturi wherein said portions arefluidicly connected to said valve; c. an axial rotator outside of saidflow path adapted to rotate at least one of said portions of said splitventuri without substantially engaging said portion within said flowpath.
 87. A split venturi valve as described in claim 86 wherein saidaxial rotator is located outside of said flow path in a location thathas less than 20% interference with a flow efficiency by said axialrotator relative to a location inside said flow path.
 88. A splitventuri valve as described in claim 86 wherein at least said secondportion of said split venturi comprises an eccentric portion.
 89. Asplit venturi valve as described in claim 86 wherein at least saidsecond portion of said split venturi comprises a semicircular eccentricportion.
 90. A split venturi valve as described in claim 86 wherein saidfirst and second portions are adapted to axially align relative to eachother for full flow.
 91. A split venturi valve as described in claim 86wherein at least said second portion of said valve is adapted tosubstantially prevent flow separation throughout said portion beginningat an interface between said first and second portions.
 92. A splitventuri valve as described in claim 86 wherein said valve is adapted toestablish a loss coefficient of 4 or less.
 93. A split venturi valve asdescribed in claim 86 further comprising a first seal located betweensaid first and second portions in a transition flow zone wherein saidfirst seal comprises an outer periphery seal and a diametrical seal insubstantially the same plane as said outer periphery seal
 94. A splitventuri valve as described in claim 86 further comprising an internalelbow fluidicly connected to one of said portions.
 95. A split venturivalve as described in claim 86 further comprising an exit port connectedto said second portion and an exit port seal at an exit port interfacebetween said exit port and a valve outlet fluidicly connected to saidvalve.
 96. A split venturi valve as described in claim 86 wherein saidaxially-rotated valve further comprises a conduit and further comprisinga cartridge assembly adapted for insertion in said conduit comprising atleast one of said portions.
 97. A split venturi valve as described inclaim 96 further comprising a cartridge seal assembly around saidcartridge assembly adapted to seal cartridge assembly in said conduit.98. A split venturi valve as described in claim 86 wherein said valvecomprises a freeze resistant valve comprising a first seal at aninterface between said first and second portions located a freezedistance away from freezing conditions.
 99. A method of providingimproved flow from a valve using a split venturi comprising: a. flowinga fluid with a pressure and velocity into an axially-rotated valvehaving a central axis; b. gradually reducing said pressure of said fluidwhile increasing said velocity of said fluid in a first portion of asplit venturi; c. flowing said fluid into a second portion; d. graduallyincreasing said pressure of said fluid while decreasing said velocity ofsaid fluid in a second portion of a split venturi comprising avoidingflow separation of said fluid in said second portion; e. axiallyrotating at least one of said portions of said split venturi along alongitudinal axis parallel to said central axis to at least a partiallyclosed position; f. at least partially restricting said fluid fromflowing through said axially-rotated valve; g. axially rotating saidrotated portion along said longitudinal axis to at least a partiallyopen position; h. allowing said flowing of said fluid.
 100. A method ofproviding improved flow from a valve as described in claim 99 whereinaxially rotating at least one of said portions of said split venturicomprises axially rotating said second portion.
 101. A method ofproviding improved flow from a valve as described in claim 99 whereinavoiding flow separation of said fluid in said second portion comprisesproviding a streamlined flow slope surface.
 102. A method of providingimproved flow from a valve as described in claim 99 wherein graduallyincreasing said pressure of said fluid while decreasing said velocity ofsaid fluid in said second portion comprises gradually increasing througha slope of approximately 7-8 degrees in said portion.
 103. A method ofproviding improved flow from a valve as described in claim 99 furthercomprising planar sealing between said first and second portions of saidsplit venturi with an outer periphery seal and a diametrical seal insubstantially the same plane as said outer periphery seal.
 104. A methodof providing improved flow from a valve as described in claim 99 whereingradually increasing said pressure comprises gradually increasing in anon-axisymmetric flow path relative to said central axis.
 105. A methodof providing improved flow from a valve as described in claim 104wherein gradually reducing said pressure comprises gradually reducing ina non-axisymmetric flow path relative to said central axis.
 106. Amethod of providing improved flow from a valve as described in claim 105wherein non-axisymmetric flow paths comprises semicircular eccentricnon-axisymmetric flow paths.
 107. A method of providing improved flowfrom a valve as described in claim 99 wherein gradually increasing saidpressure comprises gradually increasing said pressure while maintainingstreamlined flow.
 108. A method of providing improved flow from a valveas described in claim 107 wherein gradually reducing said pressurecomprises gradually reducing said pressure while maintaining streamlinedflow.
 109. A method of providing improved flow from a valve as describedin claim 108 wherein gradually reducing said pressure comprisesgradually reducing said pressure while maintaining non cavitation flow.110. A method of providing improved flow from a valve as described inclaim 99 wherein gradually reducing said pressure comprises graduallyreducing said pressure while maintaining non cavitation flow.
 111. Amethod of providing improved flow from a valve as described in claim 99further comprising establishing a loss coefficient of 4 or less throughsaid axially-rotated valve.
 112. A method of providing improved flowfrom a valve as described in claim 99 further comprising at leastpartially sealing at an interface between said portions.
 113. A methodof providing improved flow from a valve as described in claim 99 furthercomprising reducing a flow area of said flow path at an interfacebetween said first and second portions to not less than approximately40% relative to said flow area in a full cross sectional area of saidflow path.
 114. A method of providing improved flow from a valve asdescribed in claim 112 wherein sealing at said interface compriseslinearly sealing across a diametrical portion of said interface.
 115. Amethod of providing improved flow from a valve as described in claim 112wherein sealing at said interface comprises curvilinearly sealing acrossa diametrical portion of said interface.
 116. A method of providingimproved flow from a valve as described in claim 112 wherein sealingwith a cross sectional seal area to maintain a seal against fullpressure.
 117. A method of providing improved flow from a valve asdescribed in claim 99 further comprising flowing through a longer flowpath in said second portion than said first portion.
 118. A method ofproviding improved flow from a valve as described in claim 99 furthercomprising flowing through an interface between said first and secondportion wherein said first and second portions at said interfacecomprises an approximately zero slope.
 119. A method of providingimproved flow from a valve as described in claim 99 wherein rotating atleast one of said portions comprises axially rotating said portion withan axial rotator outside of said flow path without substantialinterference with flow efficiency.
 120. A method of providing improvedflow from a valve as described in claim 99 wherein rotating said secondportion comprises axially rotating said portion with an axial rotatoroutside of said flow path without substantial interference with flowefficiency.
 121. A split venturi valve comprising: a. an axially rotatedvalve having a central axis and a flow path; b. a first portion of asplit venturi having a first longitudinal axis parallel to said centralaxis; c. a second portion of a split venturi fluidicly connected to saidfirst portion and having a second longitudinal axis parallel to saidcentral axis; d. a valve rotator attached to at least one of saidportions of said split venturi wherein said second portion of said splitventuri is adapted to substantially prevent flow separation throughoutsaid second portion of said valve beginning at an interface between saidfirst and second portions.
 122. A split venturi valve as described inclaim 121 wherein said valve rotator is adapted to axially rotate atleast one of said portions along said longitudinal axis of said portion.123. A split venturi valve as described in claim 121 wherein said secondportion of said split venturi that is adapted to substantially preventflow separation throughout said second portion of said valve comprises astreamlined flow slope surface.
 124. A split venturi valve as describedin claim 121 wherein said second portion of said split venturi comprisesa slope of approximately 7-8 degrees.
 125. A split venturi valve asdescribed in claim 121 further comprising a seal located between saidfirst and second portions of said split venturi and substantiallytransverse to said central axis wherein said seal comprises an outerperiphery seal and a diametrical seal in substantially the same plane assaid outer periphery seal.
 126. A split venturi valve as described inclaim 121 wherein said flow path through said second portion comprises anon-axisymmetric flow path relative to said central axis.
 127. A splitventuri valve as described in claim 126 wherein said flow path throughsaid first portion comprises a non-axisymmetric flow path relative tosaid central axis.
 128. A split venturi valve as described in claim 127wherein non-axisymmetric flow paths comprises semicircular eccentricnon-axisymmetric flow paths.
 129. A split venturi valve as described inclaim 121 wherein said first portion of said split venturi is adapted tosubstantially prevent flow separation throughout said first portion ofsaid valve.
 130. A split venturi valve as described in claim 121 whereinat least one of said portions is adapted to substantially preventcavitation throughout said portion beginning at an interface betweensaid first and second portions.
 131. A split venturi valve as describedin claim 126 wherein at least one of said portions is adapted tosubstantially prevent cavitation throughout said portion beginning at aninterface between said first and second portions.
 132. A split venturivalve as described in claim 121 wherein said portions are to establishan overall loss coefficient of 4 or less.
 133. A split venturi valve asdescribed in claim 121 further comprising a first seal at an interfacebetween said first and second portions.
 134. A split venturi valve asdescribed in claim 121 wherein said flow path comprises a flow area andwherein said flow area at an interface between said first and secondportions further comprises a flow area not less than approximately 40%relative to said flow area in a full cross sectional area of said flowpath.
 135. A split venturi valve as described in claim 133 wherein saidfirst seal comprises a linear diametrical seal across said interface.136. A split venturi valve as described in claim 133 wherein said firstseal comprises a curvilinear diametrical seal across said interface.137. A split venturi valve as described in claim 133 further comprisinga cross sectional seal area to maintain a seal against full pressure.138. A split venturi valve as described in claim 121 wherein said secondportion has a longer flow path than said first portion.
 139. A splitventuri valve as described in claim 121 further comprising an interfacebetween said first and second portions wherein a slope of said first andsecond portions approximates zero at said interface.
 140. A splitventuri valve as described in claim 121 wherein said valve rotatorfurther comprises an axial rotator outside of said flow path adapted torotate at least one of said portions without substantial engagement ofsaid portion within said flow path.
 141. A split venturi valve asdescribed in claim 121 wherein said valve rotator further comprises anaxial rotator outside of said flow path adapted to rotate said secondportion relative to said first portion without substantial engagement ofsaid second portion within said flow path.
 142. A split venturi valve asdescribed in claim 121 further comprising a purge port assembly adaptedto open and allow drainage of said valve when said valve is in at leasta partially closed position.